When I lived in NYC my upgrade rate as an EXP was very good but things happen like weather or irregular ops to ruin that, particularly to high paid F markets like ORD and MIA. Some years back I was number 16 on the upgrade list going to ORD on a Monday morning. Interestingly, this year now MIA based my upgrade success rate has vastly improved, some of that likely due to more US flying (which in 2 weeks becomes a mute point). The only CK boarding I have ever seen was when an AA rep actually walked a CX to the gate and preboarded-seen it a lot at JFK and LAX-the Hollywood crowd.